Mac money-savers: 12 essential free Mac apps

Excellent programs to help you get the most from your Mac

7. Skim Mac OS X 10.4. or higher Mac OS X's built-in Preview application is good, but it is also lacking in some areas when it comes to working with PDFs. Skim is a free and lightweight PDF application which lets you not only view PDFs, but also lets you add and edit notes to the file, highlight text in different ways, take snapshots, create presentations with transitions, magnify documents and add bookmarks. It even supports the Apple Remote control and can automatically download remote PDFs. What more could you need from a PDF viewer?

8. iMedia Browser Mac OS X 10.4. or higher iMedia Browser takes the concept of Apple's media browser found in iLife and iWork and extends it to Finder. Essentially, it lets you browse your media without having to open any specific application in order to be able to see a preview. It is able to detect your library folders for programs including Apple's own Aperture, iPhoto, iTunes, GarageBand, your Movies folder and your web bookmarks. Additionally, you can drop any folder into the source list to quickly preview its contents.

9. Audacity MacOS X 10.4. or higher Audacity is a free, open source program for recording and editing audio on your Mac. It can see your internal soundcard or any third-party interface you have installed on your system and can play back and edit Vorbis, MP3, AIFF or WAV files. It's great for making podcasts or converting old tapes or vinyl to MP3s for your iPod. It also enables you to add effects, edit audio and make a mix of your audio. It can even change the speed and pitch of recordings. It really does offer some great features for a free program.

10. iSquint Mac OS X 10.3.9 or later Although it's less feature-heavy than its bigger, paid sibling VisualHub (£12/$24), iSquint is still an excellent free solution for converting video of almost any format into iPod format so you can watch it on the move on your video-capable iPod. It's very simple to use and much faster at conversion than the QuickTime Player. There's even an Advanced menu which lets more advanced users specify new frame sizes and rates and audio settings for their converted videos.

11. OnyX Versions for OS X 10.3, 10.4 and 10.5 System maintenance and cleaning is fairly important, but Apple doesn't directly provide tools for this as part of OS X. Titanium Software makes the free OnyX, and it's got some amazing features from cleaning out obsolete and temporary items and caches to rebuilding system databases, repairing permissions and customising the way OS X appears and behaves. There's a different version for each major revision of OS X.

12. iStat pro Mac OS X 10.4 or higher It's always good to be able to see information about what's going on under the hood of your Mac, either for troubleshooting purposes or just to better understand how it all works. iStat Pro is a free widget that displays practically all the stats you could ever need about your Mac including CPU load, uptime, battery status, network activity, temperatures, fan speed, running processes and more. You can show or hide any sections and arrange them as you like, even changing the colour of the widget.